Barrel type tappet



Aug. 31, 1937. JJLQDQsTAL 2,091,674

BARREL TYPE TAPPET Original Filed July 29, 1935 Y I INVENTOR. Jb-5ep% 05222. BY

ATTORNEYLS.

Patented Aug. 31, 1937 BARREL T PATENT OFFICE YPE TAPPET Joseph L. Dostal, Birmingham, Mich, assignor, by mesne assignments, to Eaton Manufacturing Company, Cleveland Ohio Ohio, a corporation of Original application July 29, 1935, Serial No. 33,719. Divided and this application October 24, 1936, Serial No. 107,311

7 Claims.

This invention relates to barrel type tappets for internal combustion engines and more especially to an open top type of cast metal or alloy tappets, and the present application is a division of my co- 5 pending application Serial No. 33,719, filed July 29, 1935, for Barrel type tappet.

It is an object of the invention to provide in a tappet construction affording the maximum amount of peripheral openings, consistent with satisfactory wear, bearing and strength quality of the tappet, for quick and positive drainage of oil from the interior of the tappet and to reduce the weight of the tappet and any load carried thereby.

Another object is to so shape, distribute and arrange peripheral openings in a cast, barrel type tappet of the open top type that substantially constant and equalized amounts of. metal are presented at all times to the grinding wheels of a centerless grinder.

A further object is to provide, in an open top type of valve tappet, a guiding and centering means for a push rod, or other valve operating elements, so that, in the event that an. engine valve is caused to float or stick in open position, a push rod or other valve operating element will be properly guided with reference to its seat in the tappet.

Other objects, features and advantages will become apparent from the following description of the appended claims. I I

For the purpose of illustrating the genus of the invention, a typical concrete embodiment is shown in the accompanying drawing, in which:

Figure 1 is a side elevation of a tappet construction carrying out the principles of this invention;

Fig. 2 is a generally vertical section taken sub-, stantially along the line 2-2 of Fig. 1; and

Figs. 3 and 4 are horizontal sections taken on the lines 3-3 and 4-4 of Fig. 1.

The present tappet construction is particularly adapted for high speed internal combustion engines in which lightness of. tappets and loads carried or operated thereby is essential, and in which large quantities of oil are circulated through the engine during operation. An open top, barrel type tappet of a large diameter is employed and in which provision is made for quickly draining the hollow interior of the tappet so as to reduce the effective weight of the same and any oil load carried thereby to a minimum. The walls of the tappet are provided with the maximum amount of openings consistent with satisfactory wear, bearing surface and strength,

and the edges of all of the openings are beveled so that longitudinal reciprocation of the tappets facilitates quick and positive drainage from the hollow interior to the external periphery of the tappet. The marginal walls of such openings flare outwardly so that lubricating pockets are provided for the purpose of lubricating tappets and its guide, the lower pockets dropping accumulated oil into the crank case as these openings are uncovered at the bottom of down stroke of the tappet.

Referring to the drawing, an open top, barrel type tappet I is provided with a tubular body and a cam engaging portion I I and is open at its upper end as indicated at I2. The cam engaging portion l I is provided with a partial spherical surface I5 adapted to receive a correspondingly shaped end of a push rod I4 or other valve operating cam. The rounded end I1 of the push rod I4 is preferably formed on an enlarged end portion I6 which is adapted to cooperate with the reinforcing and centralizing annular rib 2U integral with the peripheral wall of the tappet Ill and extending radially inwardly from the inner peripheral wall of the tappet body. The length of the enlarged cylindrical portion I6 of push rod I4 and the distance between the centralizing guide and the seating surface I5 of cam engaging portion I I are both greater than the normal travel of. the engine valve to be operated. The centralizing and reinforcing guide rib- 2B is preferably cast integral with the tappet I0 and cooperates with the enlarged cylindrical end portion I6 of push rod I4 to guide and maintain the push rod or valve operating cam I4 in approximate alignment with the seating surface I5 so that if an engine valve operated by tappet I0 should float or become stuck in open position,

I the push rod I4 would be guided back to its seating surface I5 on release of the engine valve.

The tubular body of the tappet Ill is provided with a plurality of windows or openings 25, each having marginal walls or edges 26 flaring outwardly so that the cross-sectional area of the windows or openings gradually increases from the inside to the outside periphery of the walls of the tappet I0. Thus, reciprocation of the tappet in the direction of its longitudinal axis in either sense causes a sharp edge 21 and a beveled or outwardly flared surface 26 to create a generally radially outward movement of oil, oil vapor, or oil mist. This causes oil to accumulate in pockets formed between the lower portion of the outwardly flared marginal walls 26 of the windows 25 and the bore of the tappet guide and maintains lubricant between the tappet and the guide therefor. The tappet is adapted to be so arranged within the tappet guide that the lower margins of the lower windows 25 will drop below the lower end of the guide for the tappet so that oil is continuously pumped from the hollow interior of the tappet and thus back into the crank case of the engine. Thus each tappet is continuously relieved of the major portion of its load of oil and the weight of the tappet and oil is maintained at a minimum during engine operation.

The outer periphery surface of the body In of the tappet is preferably ground in a centerless grinder and the openings or windows 25 are of such size and shape, and are so arranged within the walls of the tappet body, that substantially equal areas of openings and metal are presented at all times to the guiding wheels of a eenterless grinder. This prevents the appearance of high and low spots in the outer periphery surface of the tappet it. To this end, the openings 25 are equally spaced about the periphery of the tappet i 0 but arranged helically so as to take on a somewhat spiraled form in the tappet walls and thus equalize the area of openings and metal exposed to the grinding Wheels of a centerless grinder. This enables the tappet to be ground true to diameter with the minimum number of operations, and avoid the formation of high and low spots in the outer periphery surface of the tappet body. The angle of the helix will vary according to the diameter of the tappet as well as the length of the openings or Windows 25 in the tappet Walls. The openings or windows 25 extend in a generally longitudinal direction and are interrupted by wall portions 28 at points intermediate the length of the tappet. The annular rib 20 provided on the inner periphery surface of the walls of the tappet l0 also reinforces the metal of the Wall portion 28 which interrupts the openings or windows 25. Thus, the annular rib 29 reinforces and strengthens the wall structure of the tappet as well as affording a guiding means for causing proper seating of the push rod E4.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be had without departing from the spirit thereof, it is intended that all matter contained in the above description and as shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In combination with an operating part for an engine valve of an internal combustion engine,

a valve tappet comprising a tubular body closed at one end and open at the opposite end for operating such part, said closed end being provided with a seating surface for said part, and means directed inwardly from the walls of said tubular body and arranged intermediate the ends thereof for guiding said part into approximate alignment with respect to the seating surface therefor. v

2. In combination with an operating part for an engine valve of an internal combustion engine, a valve tappet comprising a tubular body closed at one end and open at the opposite end for operating such part, said closed end being provided with a seating surface for said part, and means including an inwardly directed annular rib integral with said tubular body and arranged intermediate the ends thereof for maintaining said engine valve operating part in alignment with reference to the seating surface provided therefor at the closed end of said body.

3. In combination with engine valve operating part, a valve tappet for internal combustion engines of the overhead valve type comprising a tubular body closed at one end and open at the opposite end, said closed end being provided with a seating surface for said valve operating part, and means integral with said tubular body and arranged intermediate the ends thereof for maintaining said valve operating part in approximate alignment with said seating surface.

4. In combination with an engine valve operating part, a valve tappet for internal combustion engines of the overhead type and comprising a tubular body closed at one end and open at the opposite end, said closed end being provided with a seating surface for said engine valve operating part, and means integral with the tubular body and directed inwardly therefrom at a point intermediate the ends of said body for confining the engine valve operating part to motion approximately along its longitudinal axis.

5. In combination withan operating part for an engine valve of an internal combustion engine, a valve tappet comprising a tubular body open at one end and closed at the opposite end and provided with helically openings in the walls thereof, portions of the Walls of said tubular body interrupting said openings at points intermediate the lengths of said openings, said closed end being provided with a seating surface for said part, and means directed inwardly from the portions of the Walls of said tubular body which interrupt said'openings for guiding said part into approximate alignment with reference to the seating surface therefor and for reinforcing the walls of the tappet.

6. In combination with an operating part' for an engine valve of an internal combustion engine, a valve tappet comprising a tubular body open at one end and closed at the opposite end and provided with helically arranged and elongated open ings in the walls thereof, portions of the walls of said tappet body interrupting said openings at points intermediate the lengths of said openings, said closed end being provided with a seating surface for said part, and means includingan annular rib integral with said tubular body and projecting inwardly from the portions of the walls of said tubular body which interrupt the openings for maintaining said engine valve operating parts in approximate alignment with the seating surface provided therefor on the closed end of said body and for reinforcing the walls of thetappet.

7. In combination with an operating partfor an'engine valve of an internal combustion engine, a valve tappet comprising a tubular body open at one end and closed at the opposite end and provided with helically arranged and elongated openings in the walls thereof, portions of the walls of said tubular body interrupting said openings at points intermediate the lengths of said openings, said closed end being provided with a seating surface for said part, and means integral with the walls of said tubular body and directed inwardly from the portions thereof which interrupt said openings for guiding said part into approximate alignment with respect to the seating surface therefor and for reinforcing the wall I structure of the tappet.

. I JOSEPH L, DOSTAL.

arranged and elongated 

